One Piece Chapter 10, page 4-8: Incident at the Tavern

Nami warns Luffy that the pirates will sell him off, but Luffy cheerfully suggests she join his crew. Nami refuses but offers to give him the cage key. Suddenly, Buggy appears behind her, revealing he knows she is a thief.

Buggy accuses Nami of betraying Luffy, which Luffy denies since they aren't partners. Buggy declares a severe punishment for trying to steal his treasure and orders his men to load the special Buggy Balls.

Buggy's crew prepares a massive cannon loaded with a Buggy Ball. Buggy smiles wickedly, preparing a demonstration of his power, leaving Nami and Luffy sweating in shock.

The cannon fires, completely obliterating a row of buildings in a massive explosion. Buggy boasts that with his Buggy Balls and Devil Fruit powers, he will rule the Grand Line.

Buggy orders Nami to prove her loyalty by firing the cannon to blow Luffy to pieces. Horrified, Nami tries to stall by suggesting they drink more instead.